Actuators are very practical and are used in a great variety of electronic devices. Actuators are chiefly of two types: switches and pucks. These terms can be immediately recognized by those skilled in the art.
A switch is a component to be soldered or glued to a printed circuit board at a position where the electrical contact must be set up. The switch however has the disadvantage of requiring soldering or bonding, and this is not necessarily always possible or desirable.
A puck generally has the shape of a pebble. The base of the pebble can be round or have the shape of a metallic imprint on which it is supposed to make a contact. The puck comprises a conductive surface at one of its ends. This conductive surface is generally made by means of conductive ink or any other relatively inexpensive conductive material. Indeed, with a view to cost reduction, since pucks are not essential elements of the electronic device, low-cost materials are used. Besides, a puck is actuated by a rod (situated opposite the conductive part). The rod must be firm enough to ensure pressure on the electrical contact. When the rod is elastic, it can more easily accept dimensional variations. Whether elastic or not, this rod is often directly integrated with another element situated on the surface of an electronic device and accessible to the user. The puck can then be actuated by means of this rod.
In another example, a puck can also be directly integrated with the keys of the keyboard or keypad. These are for example silicone keypads of computers, remote control units, certain payment terminals, etc.
One of the problems of a puck is that it does not necessarily age very well: in the long term, repeated action on a key of the keypad can damage the conductive surface of the puck and make the key inoperative. Indeed, a puck does not ensure quality electrical contact when a low-cost conductive material is used. Besides, this is why large-sized pucks are often seen with metal imprints that are also large in size. Now, such configurations are not always possible. In addition, the puck is not necessarily “coupled” with another element. This means that, at assembly, difficulties can arise in ensuring an accurate position of a puck which is, so to speak, floating: there can be problems with the final position of the puck. Finally, very often, the deformable material of the puck is used as a return means (like a spring) to ensure that the puck resumes its initial position after having been acted upon. This plays a role in the rapid deterioration of the puck.
There is therefore need for an actuator that can have the advantages of the puck while at the same time avoiding its drawbacks.